Problem with transmission range of AM HIRK 433MHz

I have a AM HIRK 433MHz receiver and when I'm transmitting signals to it the range is only about 2m compared with 80m as stated in the datasheet.
I have been using a 1/4 wavelength antenna, and have changed to a 1/2 wavelength antenna. This is slightly better but only about 7m. Has anyone got any ideas as to why this is so?

Maybe your transmitter or receiver module is faulty.

Maybe there is noise on the freqency where you are testing or other transmissions close to the frequency.

Are you testing line-of-sight or through walls? Maybe there is lots of metal in your walls.